Anyu Du

Achieving rapid and scar-free wound repair is a key goal in the field of regenerative medicine. Herein, a dynamically Schiff base-crosslinked hydrogel (F/R gel) with phase-adaptive regulating functions is constructed to integratedly promote rapid re-epithelization with suppressed scars on chronic infected wounds. Specifically, the gel effectively eliminates multidrug-resistant bacterial biofilm at infection stage via antimicrobial activity of ε-polylysine firstly dissociated from hydrogel matrix in infectious microenvironment, and interrupts the severe oxidative stress-inflammation cycle at wound site by the released ceria nanozyme, thus stimulating a pro-regenerative environment to ensure tissue repair. Subsequently, fibroblast growth factor/c-Jun siRNA co-loaded microcapsules gradually disintegrate to release drugs, facilitating neoangiogenesis and cell proliferation but simultaneously blocking c-Jun overexpression for fibrotic scar suppression. Notably, the F/R gel facilitates normal-like skin regeneration with no perceptible scars formed on infected male mouse wound and female rabbit ear wound models. Our work offers a promising regenerative strategy emphasizing immunomodulatory and fibroblast subtype modulation for scarless wound repair. It is challenging to achieve scar-free repair of chronic wounds as they often feature the occurrence of multiple healing phases in an unpredictable and nonlinear manner. Here, the authors report a healing phase-adaptive regulating hydrogel that exhibits hierarchically delivering performance for programmed modulation of chronic infected wounds.

influx and subsequently activated p-CaMKII/eNOS pathway, and which in turn triggered the ROS production. Consequently, over-activation of TRPM2 ion channel results in excessive apoptosis and weaker angiogenesis during SCI recovery. Inhibition of TRPM2 with 2-Aminoethyl diphenylborinate (2-APB) or TRPM2 siRNA will ameliorate the apoptosis of ECs and promote angiogenesis, subsequently enhance BSCB integrity and improve the locomotor function recovery of diabetes combined with SCI rat. In conclusion, TRPM2 channel may be a key target for the treatment of diabetes combined with SCI rat.

Oxidative stress (OS) is one of the crucial molecular events of secondary spinal cord injury (SCI). Basic fibroblast growth factor (bFGF) is a multipotent cell growth factor with an anti-oxidant effect. However, bFGF has a short half-life in vivo, which limits its therapeutic application. Biodegradable polymers with excellent biocompatibility have been recently applied in SCI. The negative aspect is that polymers cannot provide a significant therapeutic effect. Betulinic acid (BA), a natural anti-inflammatory compound, has been polymerized into poly (betulinic acid) (PBA) to serve as a drug carrier for bFGF. This study explores the therapeutic effects and underlying molecular mechanisms of PBA nanoparticles (NPs) loaded with bFGF (PBA-bFGF NPs) in SCI. Results show that PBA-bFGF NPs produce remarkable biocompatibility in vivo and in vitro. The results also demonstrate that local delivery of PBA-bFGF NPs enhances motor function recovery, inhibits OS, mitigates neuroinflammation, and alleviates neuronal apoptosis following SCI. Furthermore, the results indicate that local delivery of PBA-bFGF NPs activates the nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling pathway following SCI. In summary, results suggest that local delivery of PBA-bFGF NPs delivers potential therapeutic advantages in the treatment and management of SCI.